1. Field of the Invention
This invention relates to a truck-mounted carpet cleaning unit.
2. Description of the Prior Art
Many machines have been developed for cleaning carpets which are normally brought to the work site in a truck or van. Usually the main power plant for the unit is mounted in the truck and the only equipment brought into the building at the work site is a vacuum wand and hoses. The hoses are connected between the nozzle of the wand and the machinery in the truck and, typically, one hose is used for transporting the cleaning fluid while another hose is used for drawing a vacuum in order to pull dirt and used cleaning fluid from the carpet.
Usually the equipment mounted in the truck includes cleaning fluid supply tanks, an electric heater for heating the cleaning fluid, a pump for moving the fluid to the wand, a vacuum pump for withdrawing the fluid from the wand, and a vacuum box for temporarily storing the dirt and cleaning fluid drawn out of the carpet.
Specifically, prior art truck-mounted cleaning units have included multiple cleaning fluid tanks mounted on portable frames and at least one hose and hose reel as disclosed in U.S. Pat. No. 4,154,578, issued May 15, 1978 to Bane. Other cleaning units, such as the invention described in U.S. Pat. No. 4,158,248, issued June 19, 1979 to Palmer, have chemical storage and supply tanks mounted on one side of the truck.
Also, U.S. Pat. No. 4,109,340, issued Aug. 29, 1978 to Bates, discloses a truck-mounted cleaning apparatus in which the cleaning fluid is used as the engine coolant and the engine operates as a heat exchanger, heating the cleaning fluid prior to being sprayed on the rug.
Other U.S. Pat. Nos. 2,555,822, issued June 5, 1951 to Smith, and 3,341,081, issued Sept. 12, 1967 to King, describe the heating of a fluid by the heat generated from an internal combustion engine.
In other prior art cleaning units, in order to provide power to the heater as well as to the pumps, it is usually necessary for the operator to connect his equipment to the electrical system of the building in which the carpet is being cleaned. Under certain conditions it is necessary for the operator to connect his equipment in a number of separate electrical outlets involving more than one circuit to avoid overloading the circuitry in the building.